There have been more cases of underground cables being cut and damaged as a result of road works and construction projects, as well as contractors not exercising due diligence.

Such incidents, called cable cuts, have grown steadily over the past three years, Minister for Communications and Information Yaacob Ibrahim told Parliament yesterday.

There were seven cases last year, up from four each in 2013 and 2014. There have already been three cases this year, he added.

He was answering a question from Mr Zaqy Mohamad (Chua Chu Kang GRC) on the frequency of such incidents and what is being done to reduce them.

Such incidents can lead to disruptions to telecommunication and media services for thousands of subscribers, leaving households and businesses without fixed phone lines or television and Internet access for hours.

On Jan 17, a contractor working on Project Jewel, a retail and lifestyle complex, caused a cable cut near Changi Airport Terminal 1.

Five days later, some 2,000 households in the Sengkang area were affected by a fibre cut when a PUB contractor carried out drainage and sewer works along the Central Expressway and at Ang Mo Kio Avenue 5 junction.

The latest incident occurred on Feb 17, when a fibre optic cable cut in the Commonwealth and Ghim Moh area brought down Internet connection for households in the vicinity.

"All 18 cable cuts from 2013 onwards were caused by third-party contractors involved in the construction of new MRT lines such as the Downtown Line and Thomson East-Coast Line, power cabling, water and sewage piping works and other development projects," said Dr Yaacob.

Investigations by the Infocomm Development Authority of Singapore (IDA) show that these cable cuts were due to contractors not exercising due diligence and caution.

In three of the 18 incidents, none of the contractors engaged licensed telecom cable detection workers to be on site .

They also did not comply with standard operating procedures such as verifying the location of telecommunication cables before starting earthworks, or protecting underground cables when the works were carried out.

Dr Yaacob said the IDA is working closely with public agencies and telecom operators on preventive measures.

The agency has directed all telcos to indicate GPS (global positioning system) geographical coordinates for new deployments of telecommunication cables and manholes on their service plans.

It has also directed them to install metallic tracer wires along new underground optical fibre cables.